We are investigating the effects of proposed inducers of cell differentiation in Dictyostelium. Our methodology involves suppressing cell differentiation by submerging the slug stage and implanting Sephadex particles soaked in the agents tested. We are particularly interested in implantation of cyclic AMP, Ca ions and other ions, ATP, and oxygen sources. We also investigate relative oxygen levels in slugs by methylene blue oxidation patterns. In addition, we are carrying out histological analyses of the relation of the spatial pattern of induction to the position of the implanted particles. To date, we have obtained evidence of induction or stimulation of differentiation by all of the agents tested above, and of an oxygen gradient in the migrating slugs.